Cosmetic brushes of the type noted above typically used for the application of make-up powder to the face have been conventionally made of goat's hair. However, there are a number of problems with the use of goat's hair including an irregular supply and inconsistencies from one batch to another. More importantly, however, such goat's hair must be irradiated or purified in some other manner for antiseptic purposes. More recently, goat's hair has been found to contain an unacceptably high rate of lice eggs, obviously very undesirable from a commercial and hygenic standpoint. In addition, many people are allergic to goat's hair.
It has, of course, been suggested to substitute synthetic bristles for goat's hair. However, while synthetic bristles for many other purposes have achieved substantial success, synthetic bristles for applying powder have not been successful, and these are used only in small amounts and then only in the cheapest cosmetic brushes. Such an inexpensive prior art cosmetic brush having a handle 12 and bristles 14' is shown in FIG. 1. The synthetic bristles heretofore used for this purpose have not had the desired fullness, nor have their qualities relating to powder pick-up and powder lay-off been satisfactory.
It is also, again of course, well known to produce crimped synthetic textile filaments and yarns. In the crimping of textile filaments, a main objective is to provide the crimp in a regular and repeated fashion as depicted in FIGS. 2A and 2B, and indeed much effort is taken to insure that the crimping gears are sharp and regular and that the filament yarns are spread out so that the crimping is accomplished in a relatively sharp and regularly repeated manner.
Moreover, textile filaments are too limp and too fine for use as make-up powder brush bristles, as these textile filaments do not normally exceed 1.0 mil in diameter and they are usually much finer, whereas make-up powder brush bristles less than 2 mils in diameter would be too limp. It has also been known to crimp coarse bristles, e.g. for hair brushes, toilet bowl brushes and the like, these brushes having bristles which have diameters of 10 mils and up.